Final answer:
The key difference between prokaryotic and eukaryotic gene regulation lies in the regulatory complexity, with prokaryotes regulating at the transcriptional level and eukaryotes at multiple stages due to cellular compartmentalization.
Step-by-step explanation:
A difference between prokaryotic and eukaryotic gene regulation involves the complexity of the regulatory mechanisms and the cellular compartmentalization. Prokaryotes regulate gene expression primarily at the level of transcription with the help of repressors and activators. In contrast, eukaryotic cells contain a nucleus and have a more sophisticated system of regulation that operates at multiple levels, including the degradation of mRNA transcripts to control protein levels. This regulation can occur at epigenetic, transcriptional, pre- and post-transcriptional, and translational levels, due to the cellular compartmentalization. Consequently, the operating mechanisms like operons are typically found in prokaryotes, where several genes are regulated together, while eukaryotes have a more complex set of regulatory elements to control gene expression independently and more precisely.